85At
Astatine
MetalloidAstatine (At) is element 85, a metalloid, in period 6 and group 17 of the periodic table. Its atomic mass is usually given as 210, it melts at 302 °C and boils at 337 °C. Discovered by Dale R. Corson, 1940.
Atomic Number85
SymbolAt
NameAstatine
Atomic Weight210 u
CategoryMetalloid
Period6
Group17
Melting Point302 °C
Boiling Point337 °C
Density7 g/cm³
Electron Config[Xe] 4f14 5d10 6s2 6p5
Discovered ByDale R. Corson, 1940